Tool/software: WEBENCH® Design Tools
Hi,
I am trying to analyse the effect of CMRR by applying RLD in the circuit below, kindly help with simulation results. I tried to do simulation with tina, but not successful to analyse the effect.
If able to supply the tina model for same with results that will be really great help for my project.
Rgds
Chandra
HI Chandra,
Attached is a simulation circuit that allows you to connect and disconnect the OPA2314 RLD circuit to the INA826 and see the improvement on CMRR.
A transient simulation is performed, adding a 60-Hz common-mode noise signal to the differential ECG signal. By changing the position of the switch on the simulation, you can add or remove the Right Leg Drive circuit, and see the improvement in the common-mode rejection of the 60-Hz signal.
Please note, I changed the OPA2314 voltage supply to unipolar 0-5V, since the OPA2314 performance is only specified for a 5.5V maximumsupply (device can tolerate an absolute max of 7-V without permanent damage). I also added the OPA333 integrator buffer driving the INA826 reference input, matching the circuit of figure 69.
1) Please see the transient simulation below without the RLD circuit, showing some of the 60-Hz common-mode noise residue still present at the INA826 output; where the INA826 rejects most of the 60-Hz common-mode signal.
2) Please see the improved transient simulation below including the OPA2314 RLD circuit, showing no trace of the 60-Hz noise present at the INA826 output after including the RLD circuit.
Please find below the TINA simulation file.
Please let me know if you have additional questions.
Thank you,
Kind Regards,
Luis Chioye
